Instituto de la Ciencia y Tecnología en América Latina (ICTAL) - Tag - EvoluciónPortal dedicado a la ciencia, el desarrollo, y los derechos humanos... 2024-03-18T13:03:04-04:00urn:md5:c3c53f2c54ac152a71614d9b9f660d3dDotclearColonial history and global economics distort our understanding of deep-time biodiversityurn:md5:e5794bf6db0aac3dbc16f61bd02f84452022-01-20T10:19:00-04:002022-01-20T10:21:02-04:00cguajonNoticieroBiologiaEvoluciónHistoria de la cienica <p><br />
Source: Nature</p>
<p> </p>
<p>Sampling biases in the fossil record distort estimates of past biodiversity. However, these biases not only reflect the geological and spatial aspects of the fossil record, but also the historical and current collation of fossil data. We demonstrate how the legacy of colonialism and socioeconomic factors, such as wealth, education and political stability, impact the global distribution of fossil data over the past 30 years. We find that a global power imbalance persists in palaeontology, with researchers in high- or upper-middle-income countries holding a monopoly over palaeontological knowledge production by contributing to 97% of fossil data. As a result, some countries or regions tend to be better sampled than others, ultimately leading to heterogeneous spatial sampling across the globe. This illustrates how efforts to mitigate sampling biases to obtain a truly representative view of past biodiversity are not disconnected from the aim of diversifying and decolonizing our discipline.</p>
<p>Main<br />
The fossil record is our only direct evidence of how life on Earth has evolved over time, and reconstructions of deep-time biodiversity provide critical insights into future biodiversity change. The fossil record, upon which these reconstructions are based, is known to be incomplete and unevenly distributed across the globe1,2,3. Various taphonomic, geological and anthropogenic factors have been shown to introduce biases into estimates of deep-time biodiversity, extinction and evolution, and decades of research have documented and attempted to analytically mitigate their effects4,5,6,7. However, considerably less attention has been paid to how historical, social and economic factors influence the global distribution of fossil occurrences, and their consequent effects on our understanding of deep-time biodiversity.</p>
<p>The natural sciences were developed around an extractive process facilitated by European colonialism in the nineteenth century. When zoological and botanical specimens were uncovered during colonial expeditions, they were shipped back to the respective imperial capitals, to be housed in museums, which were rapidly increasing in numbers to accommodate the influx of scientific material8. Many specimens collected during the colonial era are still being used for scientific purposes today by researchers based in these countries. Recently, plankton samples collected from the equatorial Pacific Ocean during the HMS Challenger expedition in the nineteenth century —that made use of the extensive colonial network and relationships developed by Great Britain during that time for the purpose of scientific exploration9—were used for a study led by British authors10. Fossil specimens were no exception, and their collection was dominated by imperial systems and exchanges11. For example, Charles Darwin aboard the HMS Beagle collected fossils in South America that were sent to London and studied by British palaeontologists12. These extractive research practices continue to this day within the natural sciences13, but especially in palaeontology where fossils and their collection underpin the discipline14.</p>
<figure style="margin: 0 auto; display: table;"><a class="media-link" href="https://www.ictal.org/public/noticias/2022/fossil_bias_wealthy_countries.png"><img alt="fossil bias wealthy countries.png, Jan 2022" class="media" src="https://www.ictal.org/public/noticias/2022/.fossil_bias_wealthy_countries_m.png" /></a></figure>
<p><br />
Cont'd.</p>
<p>LINK:<br />
<a href="https://www.nature.com/articles/s41559-021-01608-8">https://www.nature.com/articles/s41559-021-01608-8</a></p>
<p> </p>Supercomputer scours fossil record for Earth’s hidden extinctionsurn:md5:bd9dd5a32d23c37380a1dcac9fc3f7702020-01-18T13:22:00-04:002020-01-23T09:52:10-04:00cguajonNoticieroDigitalEvoluciónTecnología <p><br />Source: Nature<br /><br /><br /><br />Palaeontologists have a fuzzy view of Earth’s history. An incomplete fossil record and imprecise dating techniques make it hard to pinpoint events that happened within geological eras spanning millions of years. Now, a period that saw a boom in animal complexity and one of Earth’s greatest mass extinctions is coming into sharp focus.<br /><br />Using the world’s fourth most powerful supercomputer, Tianhe II, a team of scientists based mostly in China mined a database of more than 11,000 fossil species that lived from around 540 million to 250 million years ago. The result is a history of life during this period, the early Palaeozoic era, that can pinpoint the rise and fall of species during diversifications and mass extinctions to within about 26,000 years. It is published on 16 January in Science1.<br /><br />“It is kind of amazing,” says Peter Wagner, a palaeontologist and evolutionary biologist at the University of Nebraska–Lincoln, who was not involved in the work. Being able to look at species diversity on this scale is like going from a system where “people who lived in the same century are considered to be contemporaries, to one in which only people who lived during the same 6-month period are deemed to be contemporaries”, he writes in an essay accompanying the study2.<br /><br /><br /><br /><br />Cont'd.<br /><br />LINK:<br /><a href="https://www.nature.com/articles/d41586-020-00117-1">https://www.nature.com/articles/d41586-020-00117-1</a></p>
<p> </p>“La distancia entre el campeón del mundo de ajedrez y las máquinas es mayor que entre Usain Bolt y un Ferrari”urn:md5:cce37a81dccecba28ee4372b7a4a06822019-10-06T13:44:00-04:002019-10-06T13:44:00-04:00cguajonNoticieroDigitalEvoluciónTecnología <p><br />Fuente: El Pais<br /><br /><br /><br />Al ex campeón mundial de ajedrez Gari Kasparov aún le escuece: "No fue la primera partida que perdí contra una máquina. Fue la primera partida que perdí", dice. En 1997 Deep Blue, de IBM, ganó al vigente campeón de ajedrez, que llevaba 12 años imbatido. "Las primeras semanas fueron muy duras", dice. "Fui el primer trabajador intelectual derrotado dolorosamente por una máquina delante de todo el mundo". Kasparov admite que perdió no por la brillantez de Deep Blue, sino por su consistencia. Cometió menos errores. Kasparov pidió una tercera competición –en la primera en 1996 había ganado el humano–, pero IBM se negó: "Fue una sabia decisión estratégica", dice Kasparov.<br /><br />Por suerte para Kasparov, no fue un caso único. Aquella distancia no ha hecho más que crecer: "La distancia entre el campeón actual de ajedrez, Magnus Carlsen, y las máquinas es mayor que entre Usain Bolt y un Ferrari".<br /><br />Kasparov se ha convertido hoy en un evangelista del futuro de la inteligencia artifical y de la colaboración entre hombre y máquina. Esta lección sobre la bondad del futuro se ha dado en la primera edición de Onlife, un encuentro organizado en Milán por el diario La Repubblica con la colaboración de Lena, una asociación de periódicos europeos a la que pertenece EL PAÍS. Onlife es un neologismo inventado por el filósofo italiano Luciano Floridi que significa ese espacio donde "no hay una diferencia real entre estar online y offline, y que es una gran zona híbrida, rebautizada como onlife", según Carlo Verdelli, director de La Repubblica.<br /><br /><br /><br /><br />Cont'd.<br /><br />LINK:<br /><a href="https://elpais.com/tecnologia/2019/10/05/actualidad/1570292617_659692.html">https://elpais.com/tecnologia/2019/10/05/actualidad/1570292617_659692.html</a><br /><br /><br /></p>In search of the ‘white jaguar’urn:md5:f04d398e0ea5ca46f746da8ab7457c3a2019-09-23T08:12:00-04:002019-09-23T08:12:00-04:00cguajonNoticieroBrazilCulturaEvolución <p><br />Source: Science Magazine<br /><br /><br /><br />CHIAPAS STATE IN MEXICO—About 7 hours by kayak up the Tzendales River, our GPS receiver falls overboard and vanishes in the deep blue water. We are on the fourth day of an expedition deep into the Montes Azules Biosphere Reserve, one of Mexico's largest, most remote protected areas. On the side of the GPS was an SOS button that we could press to contact emergency services or even summon a rescue helicopter. Now, traveling up a river no one else has navigated for at least 10 years, our small group of archaeologists, guides, and observers is cut off.<br /><br />But maybe that's fitting, as we are seeking a lost city. Called Sac Balam, it was founded more than 400 years ago by the Lacandon Maya, one of several Indigenous groups in southern Mexico and Central America who resisted Spanish colonial rule for centuries.<br /><br />It wasn't the kind of Maya city tourists flock to today. Sac Balam didn't have majestic stone temples, elaborate tombs, or intricate sculptures. In fact, it was probably so unassuming that its ruins might elude an untrained eye. But hundreds of Lacandon once lived there, hidden from Spanish eyes and free to continue a way of life their ancestors had practiced for centuries: planting corn and beans, raising turkeys, weaving strong thatched roofs to resist the tropical rain, and leaving offerings to their gods in nearby caves. The Lacandon had looked at this impenetrable, remote jungle and had seen safety.<br /><br /> <br /><br /><br /><br />Cont'd.<br /><br />LINK:<br /><a href="https://www.sciencemag.org/news/2019/09/search-white-jaguar-archaeologists-travel-deep-jungle-find-lost-maya-city">https://www.sciencemag.org/news/2019/09/search-white-jaguar-archaeologists-travel-deep-jungle-find-lost-maya-city</a><br /><br /></p>The human body is a mosaic of different genomesurn:md5:dfd2ccf995ee74ad64fbb216e0812df02019-06-09T20:30:00-04:002019-06-09T20:30:00-04:00cguajonGenéticaBiologiaEvolución <p><br />Source: Nature<br /><br /><br /><br />The human body is a complex mosaic made up of clusters of cells with different genomes — and many of these clusters bear mutations that could contribute to cancer, according to a sweeping survey of 29 different types of tissue.<br /><br />It is the largest such study to date, and compiles data from thousands of samples collected from about 500 people. The results, published on 6 June in Science1, could help scientists to better understand how cancer starts, and how to detect it earlier.<br /><br />“We now appreciate that we are mosaics’, and that a substantial number of cells in our body already carry cancer mutations,” says Iñigo Martincorena, a geneticist at the Wellcome Sanger Institute in Hinxton, UK. “These are the seeds of cancer.”<br /><br /><br /><br />Cont'd.<br /><br />LINK:<br /><a href="https://www.nature.com/articles/d41586-019-01780-9">https://www.nature.com/articles/d41586-019-01780-9</a><br /><br /></p>Newly Discovered Ancient Carnivore Was Bigger Than a Polar Bear and Is True Nightmare Fuelurn:md5:7665f7541fa72cd50d89a991bb232c092019-04-19T07:45:00-04:002019-04-19T07:45:00-04:00cguajonNoticieroBiologiaEvolución <p><br />Source: Gizmodo<br /><br /><br /><br />New research describes the remains of a gigantic, four-legged mammalian carnivore that terrorized Africa some 22 million years ago.<br /><br />The name of this formidable creature is Simbakubwa kutokaafrika, which translated from Swahili means “big lion coming from Africa.” But this was no feline—it belonged to an extinct group of mammals known as hyaenodonts, which have no close relation to any species of mammalian carnivore living today. Larger than a polar bear, and with a head as big as a rhino’s, Simbakubwa spent its time as an apex predator in Eastern Africa around 22 million years ago, eventually going extinct under mysterious circumstances.<br /><br />Its fossilized remains were discovered in 1980 at an important site in western Kenya called Meswa Bridge. The researchers who found the fossils were actually looking for evidence of ancient apes. Disinclined to study the fossils further, the researchers placed the specimens, which included some cheek bones, upper and lower teeth, bits of jaw, a heel bone, and several claws, in a drawer at the National Museums of Kenya, where they sat ignored for decades.<br /><br /><br /><br />Cont'd.<br /><br />LINK:<br /><a href="https://gizmodo.com/newly-discovered-ancient-carnivore-was-bigger-than-a-po-1834136617">https://gizmodo.com/newly-discovered-ancient-carnivore-was-bigger-than-a-po-1834136617</a><br /><br /></p>Complex societies precede moralizing gods throughout world historyurn:md5:7ac44e3837f52f5c3045fe4c2d2e941d2019-03-24T14:05:00-04:002019-03-24T14:05:00-04:00cguajonNoticieroAmérica LatinaCulturaEvolución <p><br />Source: Nature<br /><br />Abstract<br /><br />The origins of religion and of complex societies represent evolutionary puzzles1,2,3,4,5,6,7,8. The ‘moralizing gods’ hypothesis offers a solution to both puzzles by proposing that belief in morally concerned supernatural agents culturally evolved to facilitate cooperation among strangers in large-scale societies9,10,11,12,13. Although previous research has suggested an association between the presence of moralizing gods and social complexity3,6,7,9,10,11,12,13,14,15,16,17,18, the relationship between the two is disputed9,10,11,12,13,19,20,21,22,23,24, and attempts to establish causality have been hampered by limitations in the availability of detailed global longitudinal data. To overcome these limitations, here we systematically coded records from 414 societies that span the past 10,000 years from 30 regions around the world, using 51 measures of social complexity and 4 measures of supernatural enforcement of morality. Our analyses not only confirm the association between moralizing gods and social complexity, but also reveal that moralizing gods follow—rather than precede—large increases in social complexity. Contrary to previous predictions9,12,16,18, powerful moralizing ‘big gods’ and prosocial supernatural punishment tend to appear only after the emergence of ‘megasocieties’ with populations of more than around one million people. Moralizing gods are not a prerequisite for the evolution of social complexity, but they may help to sustain and expand complex multi-ethnic empires after they have become established. By contrast, rituals that facilitate the standardization of religious traditions across large populations25,26 generally precede the appearance of moralizing gods. This suggests that ritual practices were more important than the particular content of religious belief to the initial rise of social complexity.<br /><br /><br /><br />Cont'd.<br /><br />LINK:<br /><a href="https://www.nature.com/articles/s41586-019-1043-4">https://www.nature.com/articles/s41586-019-1043-4</a><br /><br /></p>The ecological roots of human susceptibility to social influenceurn:md5:6099ef324479fc28af219e0e8b9751a02019-01-15T19:21:00-04:002019-01-15T19:22:06-04:00cguajonGenéticaBiologiaCulturaEvolución <br />Source: RoyalSociety Open Science<br /><br /><br /><br /><br />The ecological roots of human susceptibility to social influence: a pre-registered study investigating the impact of early-life adversity<br />Pierre O. Jacquet , Lou Safra , Valentin Wyart , Nicolas Baumard and Coralie Chevallier<br /><div>Published:09 January 2019https://doi.org/10.1098/rsos.180454</div>Abstract<br /><br />There is considerable variability in the degree to which individuals rely on their peers to make decisions. Although theoretical models predict that environmental risks shift the cost–benefit trade-off associated with social information use, this idea has received little empirical support. Here we aim to test the effect of childhood environmental adversity on humans' susceptibility to follow others’ opinion in the context of a standard face evaluation task. Results collected in a pilot study involving 121 adult participants tested online showed that susceptibility to social influence and childhood environmental adversity are positively associated. Computational analyses further confirmed that this effect is not explained by the fact that participants exposed to early adversity produce noisier decisions overall but that they are indeed more likely to follow the group's opinion. To test the robustness of these findings, a pre-registered direct replication using an optimal sample size was run. The results obtained from 262 participants in the pre-registered study did not reveal a significant association between childhood adversity and task performance but the meta-analysis ran on both the pilot and the pre-registered study replicated the initial finding. This work provides experimental evidence for an association between individuals' past ecology and their susceptibility to social influence.<br /><br />1. Background<br /><br />Modern western societies take for granted that intellectual autonomy, creativity and originality are universally valued. ‘Free-thinkers’, ‘rebels’ or ‘subversive attitudes' are indeed positively valued and parents even encourage their children to have their own opinion and to ‘be leaders rather than followers’. But such independence is in fact not highly regarded in every society and at every time in history [1]. Pre-industrial Europe, for instance, emphasized the importance of conformity and traditionalism, individuals took pride in following the ‘ancients’, and parents taught their children to be obedient, to revere their elders and to abide by the majority [2–4]. Within societies, individuals also vary in the degree to which they rely on others' views to make decisions and form opinions [5–8]. Why is that the case? Why are some environments seemingly more conducive to individual exploration while other environments promote more social forms of information acquisition?<br /><br /><br /><br />Cont'd.<br /><br />LINK:<br /><a href="https://royalsocietypublishing.org/doi/10.1098/rsos.180454">https://royalsocietypublishing.org/doi/10.1098/rsos.180454</a><br /><br /><br /><br />Mum’s a Neanderthal, Dad’s a Denisovanurn:md5:407b0e2c2fcc56846227998ef383e0d32018-08-22T14:47:00-04:002018-08-22T14:47:00-04:00cguajonNoticieroBiologiaEvolución <p><br />Source: Nature<br /><br />A female who died around 90,000 years ago was half Neanderthal and half Denisovan, according to genome analysis of a bone discovered in a Siberian cave. This is the first time scientists have identified an ancient individual whose parents belonged to distinct human groups. The findings were published on 22 August in Nature1.<br /><br />“To find a first-generation person of mixed ancestry from these groups is absolutely extraordinary,” says population geneticist Pontus Skoglund at the Francis Crick Institute in London. “It’s really great science coupled with a little bit of luck.”<br /><br />The team, led by palaeogeneticists Viviane Slon and Svante Pääbo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, conducted the genome analysis on a single bone fragment recovered from Denisova Cave in the Altai Mountains of Russia. This cave lends its name to the ‘Denisovans’, a group of extinct humans first identified on the basis of DNA sequences from the tip of a finger bone discovered2 there in 2008. The Altai region, and the cave specifically, were also home to Neanderthals.<br /><br /><br /><br />Cont'd.<br /><br /><a href="LINK: https://www.nature.com/articles/d41586-018-06004-0">LINK:<br />https://www.nature.com/articles/d41586-018-06004-0</a><br /></p>Carnivorous-dinosaur auction reflects rise in private fossil salesurn:md5:3994c428e6ad906145da91032b1fe6862018-06-03T08:16:00-04:002018-06-03T08:16:00-04:00cguajonNoticieroDerechos HumanosEconomíaEvolución <p><br />Source: Nature<br /><br /><br /><br />A fossil of a carnivorous dinosaur found in the United States is about to go under the hammer. The Parisian auction house managing the sale, scheduled for 4 June in the Eiffel Tower, says the nearly complete, nine-metre-long specimen is probably a new species, and hopes that it will fetch €1.2 million–1.8 million (US$1.4 million–2.1 million). But international palaeontologists warn that the specimen could be lost to science. They fear that a growing trend for the private sale of fossils is driving up prices, putting potentially valuable specimens beyond the reach of cash-strapped museums and public institutions.<br /><br />Auctioneer Aguttes says the fossil bears similarities to a species of Allosaurus, but has differences in features including its teeth, skull and pelvis that are significant enough for it to be considered a new species. The creature lived about 154 million years ago, during the late Jurassic period. Although palaeontologists say that detailed studies are needed to confirm that it is a new species, they agree that the fossil, excavated on private land in Wyoming between 2013 and 2015, seems to be unusual and therefore scientifically significant.<br /><br />The Society of Vertebrate Paleontology (SVP) in Bethesda, Maryland, which represents more than 2,200 international palaeontologists, has written to Aguttes, urging the auction house to cancel the sale. David Polly, the society’s president, told Nature that the society is concerned about scientifically valuable fossils going into private hands rather than a public repository where scientists can examine and interpret them. “Fossil specimens that are sold into private hands are lost to science,” the letter states.<br /><br /><br /><br /><br />Cont'd.<br /><br />LINK:<br /><a href="https://www.nature.com/articles/d41586-018-05299-3">https://www.nature.com/articles/d41586-018-05299-3</a><br /><br /><br /></p>Genes of ‘extinct’ Caribbean islanders found in living peopleurn:md5:d92283b65547cff0b36f6e22d838ada12018-02-22T07:10:00-04:002018-02-22T07:10:00-04:00cguajonGenéticaBiologiaCaribeEvolución <p><br />Source: Science Magazine<br /><br /><br /><br />Jorge Estevez grew up in the Dominican Republic and New York City hearing stories about his native Caribbean ancestors from his mother and grandmother. But when he told his teachers that he is Taino, an indigenous Caribbean, they said that was impossible. “According to Spanish accounts, we went extinct 30 years after [European] contact,” says Estevez, an expert on Taino cultures at the Smithsonian Institution’s National Museum of the American Indian, who is based in New York City.<br /><br />Many scientists and historians continue to believe the Taino were wiped out by disease, slavery, and other brutal consequences of European colonization without passing down any genes to people in the Caribbean today. But a new genetic study of a 1000-year-old skeleton from the Bahamas shows that at least one modern Caribbean population is related to the region’s precontact indigenous people, offering direct molecular evidence against the idea of Taino “extinction.”<br /><br />“These indigenous communities were written out of history,” says Jada Benn Torres, a genetic anthropologist at Vanderbilt University in Nashville who studies the Caribbean’s population history and has worked with native groups on several islands. “They are adamant about their continuous existence, that they’ve always been [on these islands],” she says. “So to see it reflected in the ancient DNA, it’s great.”<br /><br /><br /><br /><br />Cont'd.<br /><br />LINK:<br /><a href="http://www.sciencemag.org/news/2018/02/genes-extinct-caribbean-islanders-found-living-people">http://www.sciencemag.org/news/2018/02/genes-extinct-caribbean-islanders-found-living-people</a><br /><br /></p>Debate blooms over anatomy of the world’s first flowerurn:md5:8a99bcec069352d57a563ec9df9764d22018-02-06T07:42:00-04:002018-02-06T07:42:00-04:00cguajonGenéticaBiologiaEvolución <p><br />Source: Nature<br /><br /><br /><br />An ambitious effort to reconstruct the world’s first flower has seeded a debate over what forms a blossom can and cannot take.<br /><br />The project, called eFLOWER, combined an unparalleled database of plant traits, reams of molecular data on evolutionary relationships, and complex statistical models to determine what the ancestor of all modern flowering plants might have looked like. When its results were published last August1, they drew intense interest from academics and the media.<br /><br />But since then, researchers have raised questions about some of eFLOWER’s predictions. On 31 January, plant morphologist Dmitry Sokoloff of Moscow State University and his colleagues published a reanalysis of the data that suggests a different arrangement of key female reproductive structures in the first flower2.<br /><br /><br /><br /><br />Cont'd.<br /><br />LINK:<br /><a href="https://www.nature.com/articles/d41586-018-01539-8">https://www.nature.com/articles/d41586-018-01539-8</a><br /><br /></p>Skeleton plundered from Mexican cave was one of the Americas’ oldesturn:md5:03f3cd5260285fdaba7885a319bbed042017-08-31T06:36:00-04:002017-08-31T06:36:00-04:00cguajonNoticieroCulturaEvoluciónMexico <p><br />Source: Nature<br /><br /><br /><br />A human skeleton — probably one of the Americas' oldest — was stolen from the Chan Hol Cave in Mexico soon after it was discovered in 2012. <br />A human skeleton that was stolen from an underwater cave in Mexico in 2012 may be one of the oldest ever found in the Americas. Scientists have now put the age of the skeleton at more than 13,000 years old after analysing a shard of hip bone — left behind by the thieves because it was embedded in a stalagmite.<br /><br />Cave divers discovered the remains in February 2012 in a submerged cave called Chan Hol near Tulúm on Mexico's Yucatán peninsula, and posted photos of a nearly complete skull and other whole bones to social media. The posts caught the attention of archaeologists Arturo González González at the Desert Museum in Saltillo, Mexico, and Jerónimo Avilés Olguín at the Institute of American Prehistory in Cancún.<br /><br />By the time researchers visited the cave in late March, the remains were gone — except for about 150 bone fragments and a pelvic bone that had been subsumed by a stalagmite growing up from the cave floor. On the basis of these bones, the researchers think that the skeleton belonged to a young man who died when sea levels were much lower and the cave was above ground.<br /><br /><br /><br />Cont’d.<br /><br />LINK:<br /><a href="http://www.nature.com/news/skeleton-plundered-from-mexican-cave-was-one-of-the-americas-oldest-1.22521">http://www.nature.com/news/skeleton-plundered-from-mexican-cave-was-one-of-the-americas-oldest-1.22521</a><br /><br /><br /></p>Ancient genomes show how maize adapted to life at high altitudesurn:md5:d01732d5ca5cc31ad64d2031f6599d852017-08-04T05:39:00-04:002017-08-04T05:39:00-04:00cguajonGenéticaAmérica LatinaEvolución <p><br />Source: Nature<br /><br /><br />Genome sequences from nearly 2,000-year-old cobs of maize (corn) found in a Utah cave paint a portrait of the crop at the dawn of its adaptation to the highlands of the US southwest. That maize, researchers found, was small, bushy and — crucially — had developed the genetic traits it needed to survive the short growing seasons of high altitudes.<br /><br />The team’s study1, published on 3 August in Science, is remarkable in how it tackles complex genetic traits governed by the interactions of many different genes, say researchers. It uses that information to create a detailed snapshot of a crop in the middle of domestication. Such insights could help modern plant breeders to buffer crops against global climate change.<br /><br />Geneticists of both modern and ancient crops have poured tremendous effort into understanding maize, which was one of the most important subsistence crops in the New World thousands of years ago, and is a cornerstone of global agriculture today.<br /><br /><br /><br /><br />Cont’d.<br /><br />LINK:<br /><a href="http://www.nature.com/news/ancient-genomes-show-how-maize-adapted-to-life-at-high-altitudes-1.22403">http://www.nature.com/news/ancient-genomes-show-how-maize-adapted-to-life-at-high-altitudes-1.22403</a><br /><br /></p>Geckos evolve rapidly in Brazil after new dam constructedurn:md5:55e79ea4fe58150ab3a7cbf5439712832017-08-01T10:05:00-04:002017-08-01T10:05:00-04:00cguajonGenéticaBrazilEvoluciónTecnología <p><br />Source: Science Magazine<br /><br /><br /><br /><br />The construction of a dam in central Brazil has spurred remarkably fast evolution of geckos in the region. In just 15 years, the lizards’ heads have grown larger—an adaptation that allows them to eat a wider assortment of insects made available by the dam’s creation. The find may portend other rapid evolutionary changes across the globe as humans continue to dramatically alter the natural landscape. <br /><br />Starting in 1996, the dam flooded a series of valleys in Brazil’s savannalike Cerrado region, creating nearly 300 islands out of what was once high ground. Many of the area’s largest lizard species disappeared from the new islands, likely because there wasn’t enough food to support their energy needs. But a small, dragonfly-sized gecko called Gymnodactylus amarali—a termite eater once common across the flooded area—persisted on at least some of them. This created an opportunity: Larger termites, which had previously been eaten by the larger lizards, were now readily available to the geckos.<br /><br />But there was a hitch. The geckos had small heads—only 1 centimeter wide—and some of the termites were nearly the same size. Eating them presented a challenge, kind of like a house cat trying to put a squirrel in its mouth.<br /><br /><br /><br /><br />Cont’d.<br /><br />LINK:<br /><a href="http://www.sciencemag.org/news/2017/07/geckos-evolve-rapidly-brazil-after-new-dam-constructed">http://www.sciencemag.org/news/2017/07/geckos-evolve-rapidly-brazil-after-new-dam-constructed</a><br /><br /></p>US defence agencies grapple with gene drivesurn:md5:4007db71c6a1e26272c2b7d7d7282f1f2017-07-24T05:40:00-04:002017-07-24T05:40:00-04:00cguajonGenéticaEstados UnidosEvoluciónTecnología <p><br />Source: Nature<br /><br /><br /><br />The JASONs, a group of elite scientists that advises the US government on national security, has weighed in on issues ranging from cyber security to renewing America’s nuclear arsenal. But at a meeting in June, the secretive group took stock of a new threat: gene drives, a genetic-engineering technology that can swiftly spread modifications through entire populations and could help vanquish malaria-spreading mosquitoes.<br /><br />That meeting forms part of a broader US national security effort this year to grapple with the possible risks and benefits of a technology that could drive species extinct and alter whole ecosystems. On 19 July, the US Defense Advanced Research Projects Agency (DARPA) announced US$65 million in funding to scientists studying gene-editing technologies; most of the money will be for work on gene drives. And a US intelligence counterpart to DARPA is planning to fund research into detecting organisms containing gene drives and other modifications.<br /><br />“Every powerful technology is a national security issue,” says Kevin Esvelt, an evolutionary engineer at the Massachusetts Institute of Technology in Cambridge, who won DARPA funding to limit the spread of gene drives. Esvelt says he also attended last month’s JASON meeting in San Diego, California, where he outlined how would-be bioterrorists might weaponize gene drives. But he is far more concerned about the potential for accidental release of gene-drive organisms by scientists, he says. “Bio-error is what I’m worried about.”<br /><br /><br /><br /><br />Cont’d.<br /><br />LINK:<br /><a href="http://www.nature.com/news/us-defence-agencies-grapple-with-gene-drives-1.22345">http://www.nature.com/news/us-defence-agencies-grapple-with-gene-drives-1.22345</a><br /><br /><br /></p>How poverty affects the brainurn:md5:05d5f12155936973ddabe006e6488f292017-07-16T06:03:00-04:002017-07-16T06:03:00-04:00cguajonDerechos humanosEconomíaEvoluciónInternacional <p><br />Source: Nature<br /><br /><br /><br />In the late 1960s, a team of researchers began doling out a nutritional supplement to families with young children in rural Guatemala. They were testing the assumption that providing enough protein in the first few years of life would reduce the incidence of stunted growth.<br /><br />It did. Children who got supplements grew 1 to 2 centimetres taller than those in a control group. But the benefits didn't stop there. The children who received added nutrition went on to score higher on reading and knowledge tests as adolescents, and when researchers returned in the early 2000s, women who had received the supplements in the first three years of life completed more years of schooling and men had higher incomes1.<br /><br />“Had there not been these follow-ups, this study probably would have been largely forgotten,” says Reynaldo Martorell, a specialist in maternal and child nutrition at Emory University in Atlanta, Georgia, who led the follow-up studies. Instead, he says, the findings made financial institutions such as the World Bank think of early nutritional interventions as long-term investments in human health.<br /><br /><br /><br />Cont’d.<br /><br />LINK:<br /><a href="http://www.nature.com/news/how-poverty-affects-the-brain-1.22280?WT.mc_id=SFB_NNEWS_1508_RHBox">http://www.nature.com/news/how-poverty-affects-the-brain-1.22280?WT.mc_id=SFB_NNEWS_1508_RHBox</a><br /><br /><br /><br /></p>World's largest hoard of carbon dates goes globalurn:md5:056c835238c0b74ec93aea002f0701f12017-07-12T04:28:00-04:002017-07-12T04:28:00-04:00cguajonNoticieroCulturaDigitalEvolución <p><br />Source: Nature<br /><br /><br /><br />Radiocarbon dating has long been used to reveal the age of organic materials — from ancient bones to wooden artefacts. Scientists are now using the amassed dates for wider applications, such as spotting patterns in human migration. And a Canadian database is poised to help researchers around the world to organize this trove of archaeological and palaeontological data, and to address problems that have plagued carbon dating for years.<br /><br />Set up in the 1980s, the Canadian Archaeological Radiocarbon Database (CARD) is undergoing an expansion that began in 2014. The database currently holds 70,000 radiocarbon records from 70 countries. The latest effort aims to make the software behind the site open source, making it easier for other research groups to set up their own version of CARD while still contributing core information to the main database. The first such site should come online within the year.<br /><br />There are other radiocarbon databases out there, but CARD is by far the largest, says Robert Kelly at the University of Wyoming in Laramie, who is collecting data to contribute to CARD. It’s also the only one so far with global ambitions, he says. “This is big data. That’s where the action is,” says Kelly. “We’ve spent 60 years running radiocarbon dates, and you can do a lot with them if they’re all in one place.”<br /><br /><br /><br /><br />Cont’d.<br /><br />LINK:<br /><a href="http://www.nature.com/news/world-s-largest-hoard-of-carbon-dates-goes-global-1.22287">http://www.nature.com/news/world-s-largest-hoard-of-carbon-dates-goes-global-1.22287</a><br /><br /></p>Our obsession with eminence warps researchurn:md5:75780c7dbf11b34e86c90d7fb8c737212017-07-08T08:08:00-04:002017-07-08T08:08:00-04:00cguajonNoticieroCulturaEducaciónEvolución <p><br />Source: Nature<br /><br /><br /><br />We can quantify exactly how much faster Usain Bolt is than the next-fastest sprinter. It's much harder to say who is the best scientist, let alone how much better they are than the next-best scientist. Deciding who deserves recognition is, at least in part, a judgement call.<br /><br />On my optimistic days, I can believe that, despite all the noise, there's still a reliable signal: that we mostly manage to publish, fund and hire people who do the better research. As an editor, peer reviewer and grant reviewer, I have spent hours making consequential choices about others' work. It would be demoralizing to believe that I might as well have flipped a coin.<br /><br />On my more cynical days, I worry that we scientists have far too much faith in our abilities to distinguish the truly excellent. Too often we assume that researchers with more grant money, awards, publications and citations must be better than the rest. Eminence, by which I mean prestige for a specific accomplishment, position or award, is given much more weight than it should be.<br /><br /><br /><br />Cont’d.<br /><br />LINK:<br /><a href="http://www.nature.com/news/our-obsession-with-eminence-warps-research-1.22251">http://www.nature.com/news/our-obsession-with-eminence-warps-research-1.22251</a><br /><br /><br /></p>Scientists Find 100 Million-Year-Old, Nearly Complete Baby Bird Trapped in Amberurn:md5:e677732654a43439d013328026dd64382017-07-02T06:16:00-04:002017-07-02T06:16:00-04:00cguajonNoticieroEvoluciónInternacional <p><br />Source: Gizmodo<br /><br /><br /><br />This has been a huge year for finding specimens in amber, from bird wings to dinosaur feathers to this ugly-ass bug. But this new finding might be the best one yet: a nearly complete 99-million-year-old baby bird.<br /><br />Scientists found the specimen in Myanmar, where others have purchased or found plenty of other incredible amber samples in the amber mines. But this one is crazy: an almost complete baby bird that lived during the time of the dinosaurs.<br /><br />“Seeing this much of an animal preserved in amber is exciting,” study author Ryan McKellar told Gizmodo. “In this case we have the whole right side of the body.”<br /><br /><br /><br />Cont’d.<br /><br />LINK:<br /><a href="http://gizmodo.com/scientists-find-100-million-year-old-mostly-complete-b-1795901335">http://gizmodo.com/scientists-find-100-million-year-old-mostly-complete-b-1795901335</a><br /><br /></p>